CVE-2012-2803 in FFmpeg
Summary
by MITRE
Double free vulnerability in the mpeg_decode_frame function in libavcodec/mpeg12.c in FFmpeg before 0.11, and Libav 0.7.x before 0.7.7 and 0.8.x before 0.8.5, has unknown impact and attack vectors, related to resetting the data size value.
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Analysis
by VulDB Data Team • 12/13/2021
The CVE-2012-2803 vulnerability represents a critical double free condition affecting multimedia processing libraries within the FFmpeg and Libav ecosystems. This flaw resides in the mpeg_decode_frame function located in libavcodec/mpeg12.c, where improper memory management leads to potential arbitrary code execution. The vulnerability specifically manifests when handling MPEG video decoding operations, particularly during the reset of data size values, creating a scenario where the same memory block can be freed twice. Such memory corruption issues typically arise from insufficient input validation and improper state management during complex multimedia processing operations.
The technical exploitation of this vulnerability occurs through crafted malicious MPEG video files that trigger the problematic code path in the MPEG decoder. When the decoder encounters specific malformed data structures, it attempts to reset internal data size values while simultaneously managing memory allocation and deallocation processes. This creates a race condition where memory management routines attempt to free the same memory block multiple times, leading to heap corruption that can be leveraged by attackers to execute arbitrary code. The vulnerability's impact extends beyond simple denial of service as the memory corruption can be manipulated to alter program execution flow, potentially allowing remote code execution or privilege escalation depending on the target system's configuration.
From an operational perspective, this vulnerability affects a wide range of applications and systems that rely on FFmpeg or Libav for multimedia processing including video streaming platforms, media servers, content management systems, and digital signage solutions. The attack vectors remain largely unspecified in the original CVE description, but typically involve users opening or processing maliciously crafted video files through vulnerable applications. The vulnerability's presence in multiple versions of both FFmpeg and Libav means that organizations using these libraries across various software products face significant risk exposure, particularly those handling untrusted multimedia content from external sources. Security researchers have classified this vulnerability under CWE-415, representing double free conditions in memory management, which aligns with the observed behavior of the exploit.
The mitigation strategies for CVE-2012-2803 primarily focus on immediate software updates and patches from the affected vendors. Organizations must upgrade to FFmpeg versions 0.11 or later and Libav versions 0.7.7, 0.8.5, or later to eliminate the vulnerability. Additionally, implementing input validation controls and sandboxing mechanisms can provide defense-in-depth measures while waiting for patch deployment. Network-based mitigations such as content filtering and MIME type validation can help prevent exploitation by blocking potentially malicious video files from reaching vulnerable systems. The vulnerability's classification under ATT&CK technique T1203, "Exploitation for Client Execution," highlights the need for comprehensive endpoint protection measures including regular security assessments, vulnerability scanning, and monitoring for suspicious file processing activities. Organizations should also consider implementing automated patch management systems to ensure rapid deployment of security updates across their infrastructure.